U.S. patent number 6,129,701 [Application Number 09/196,042] was granted by the patent office on 2000-10-10 for vented aspirator and method.
This patent grant is currently assigned to Sound Surgical Technologies, LLC. Invention is credited to William W. Cimino.
United States Patent |
6,129,701 |
Cimino |
October 10, 2000 |
Vented aspirator and method
Abstract
An improved surgical instrument for the removal of fragmented
tissues and fluids from a patient through a small incision is
disclosed. The instrument utilizes a source of suction and a source
of irrigating fluid which suspends and dilutes the fragmented
tissues and also provides a pressure vent to improve the speed and
thoroughness of the procedure. A multi-lumen cannula is used to
deliver the irrigating fluid to the operative site, to vent the
operative site, and to remove the fragmented tissue and fluids from
the operative site.
Inventors: |
Cimino; William W. (Louisville,
CO) |
Assignee: |
Sound Surgical Technologies,
LLC (Lafayette, CO)
|
Family
ID: |
22723905 |
Appl.
No.: |
09/196,042 |
Filed: |
November 19, 1998 |
Current U.S.
Class: |
604/35;
604/30 |
Current CPC
Class: |
A61M
1/85 (20210501); A61M 1/7411 (20210501); A61M
1/774 (20210501) |
Current International
Class: |
A61M
1/00 (20060101); A61M 001/00 () |
Field of
Search: |
;604/27,30,32-35,39,404,118,119,128,129,902 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Kennedy; Sharon
Attorney, Agent or Firm: Dorsey & Whitney LLP
Claims
What is claimed is:
1. A surgical aspirator and irrigator system for use by a surgeon
for removal of fragmented tissues and fluids from a patient
comprising:
a source of suction;
a source of irrigation fluid;
a handle to be held and manipulated by the surgeon, the handle
having a distal end;
a suction connector on the handle for fluid communication with the
source of suction;
an irrigation connector on the handle for fluid communication with
the source of irrigation fluid;
a suction channel passing through the handle in fluid communication
with the suction connector;
an irrigation channel passing through the handle in fluid
communication with the irrigation connector;
a vent passageway in fluid communication between the ambient air
and the suction channel passing through the handle;
a multi-lumen cannula having at least two passages along an axis
thereof, the multi-lumen cannula supported on the distal end of the
handle;
a first passage within the multi-lumen cannula in fluid
communication with the suction channel, the first passage for
suction and aligned along the axis;
a second passage within the multi-lumen cannula in fluid
communication with the irrigation channel, the second passage for
irrigation and aligned along the axis;
a cross-section of the multi-lumen cannula perpendicular to the
axis, the cross section located anywhere along the length of the
multi-lumen cannula;
a surface area of a unit length of the first passage measured from
the cross-section;
a cross-sectional area of the first passage at the
cross-section;
a resistive ratio of the first passage that is the surface area of
a unit length of the first passage divided by the cross-sectional
area of the first passage;
a surface area of a unit length of the second passage measured from
the cross-section,
a cross-sectional area of the second passage at the
cross-section;
a resistive ratio of the second passage that is the surface area of
a unit length of the second passage divided by the cross-sectional
area of the second passage,
the resistive ratio of the first passage between 0.5 and 1.5 times
the resistive ratio of the second passage; and
the handle includes an irrigation control switch with an electrical
connection to an irrigation controller located at and operatively
connected to the source of irrigation fluid, the irrigation control
switch for initiating or inhibiting the flow of irrigation fluid by
electrically signaling the irrigation controller.
2. The surgical aspirator and irrigator system of claim 1 wherein
the source of irrigation fluid includes a supply of sterile,
biocompatible irrigation fluid.
3. The aspirator and irrigator system of claim 1 wherein the source
of irrigation fluid includes a supply of filtered, pressurized,
biocompatible gas.
4. The surgical aspirator and irrigator system of claim 1 wherein
the system includes:
a supply of sterile, biocompatible irrigation fluid, and a supply
of filtered, pressurized, biocompatible gas;
a gas connector located on the handle in fluid communication with
the supply of filtered, pressurized, biocompatible gas;
a gas channel passing through the handle in fluid communication
with the gas connector;
a two-input one-output connector located within the handle;
a first input on the two-input one-output connector in fluid
communication with the gas channel passing through the handle;
a second input on the two-input one-output connector in fluid
communication
with the irrigation channel passing through the handle;
an output on the two-input one-output connector in fluid
communication with the second passage in the multi-lumen
cannula;
a gas control valve located on the handle, the gas control valve
selectively openable or closeable so that the gas line passing
through the handle is in fluid communication with the first input
on the two-input one-output connector when the gas control valve is
open or so that the gas channel is sealed from fluid communication
with the first input on the two-input one-output connector when the
gas control valve is closed.
5. The surgical aspirator and irrigator system of claim 1 wherein
the resistive ratio of the first passage is between 0.7 and 0.9
times the resistive ratio of the second passage.
6. A surgical aspirator and irrigator system for use by a surgeon
for removal of fragmented tissues and fluids from a patient
comprising:
a source of suction;
a source of irrigation fluid;
a handle to be held and manipulated by the surgeon, the handle
having a distal end;
a suction connector on the handle for fluid communication with the
source of suction;
an irrigation connector on the handle for fluid communication with
the source of irrigation fluid;
a suction channel passing through the handle in fluid communication
with the suction connector;
an irrigation channel passing through the handle in fluid
communication with the irrigation connector;
a vent passageway in fluid communication between the ambient air
and the suction channel passing through the handle;
a multi-lumen cannula having at least two passages along an axis
thereof, the multi-lumen cannula supported on the distal end of the
handle;
a first passage within the multi-lumen cannula in fluid
communication with the suction channel, the first passage for
suction and aligned along the axis;
a second passage within the multi-lumen cannula in fluid
communication with the irrigation channel, the second passage for
irrigation and aligned along the axis;
a cross-section of the multi-lumen cannula perpendicular to the
axis, the cross section located anywhere along the length of the
multi-lumen cannula;
a surface area of a unit length of the first passage measured from
the cross-section;
a cross-sectional area of the first passage at the
cross-section;
a resistive ratio of the first passage that is the surface area of
a unit length of the first passage divided by the cross-sectional
area of the first passage;
a surface area of a unit length of the second passage measured from
the cross-section,
a cross-sectional area of the second passage at the
cross-section;
a resistive ratio of the second passage that is the surface area of
a unit length of the second passage divided by the cross-sectional
area of the second passage,
the resistive ratio of the first passage between 0.5 and 1.5 times
the resistive ratio of the second passage;
a supply of sterile, biocompatible irrigation fluid, and a supply
of filtered, pressurized, biocompatible gas;
a gas connector located on the handle in fluid communication with
the supply of filtered, pressurized, biocompatible gas;
a gas channel passing through the handle in fluid communication
with the gas connector;
a two-input one-output connector located within the handle;
a first input on the two-input one-output connector in fluid
communication with the gas channel passing through the handle;
a second input on the two-input one-output connector in fluid
communication with the irrigation channel passing through the
handle;
an output on the two-input one-output connector in fluid
communication with the second passage in the multi-lumen
cannula;
a gas control valve located on the handle, the gas control valve
selectively openable or closeable so that the gas line passing
through the handle is in fluid communication with the first input
on the two-input one-output connector when the gas control valve is
open or so that the gas channel is sealed from fluid communication
with the first input on the two-input one-output connector when the
gas control valve is closed.
7. The surgical aspirator and irrigator system of claim 6 wherein
the resistive ratio of the first passage is between 0.7 and 0.9
times the resistive ratio of the second passage.
Description
TECHNICAL FIELD
This invention relates generally to surgical instruments, and, more
particularly, to a surgical device for use in aspirating fragmented
tissue and fluids from a patient.
BACKGROUND OF THE INVENTION
Liposuction is a surgical procedure for altering the human form,
specifically by removal of localized deposits of fat tissues that
are unresponsive to diet or exercise. The procedure is also known
as suction lipectomy, lipolysis, and more recently as body contour
surgery or body sculpting surgery. It is most often performed by
plastic surgeons, although dermatologists, gynecologists, and other
surgical specialties also perform the procedure.
The procedure is typically accomplished by inserting a small
cannula through an incision in the skin, applying a suction source
to the end of the cannula that remains outside of the body, and
forcing the working end of the cannula forward and backward in the
layer of fatty tissue. The fatty tissue is torn, crushed, or
avulsed, and is then aspirated through small openings along the
sides of the cannula near the tip and then through a central lumen
in the cannula to a tissue canister placed in-line with the cannula
and the suction source. The procedure may involve multiple
incisions and many passes of the cannula in each incision to
achieve the desired cosmetic effect for the patient.
A liposuction cannula is typically a small metal tube with a blunt,
closed end at the tip. The blunt, closed end at the tip is intended
to minimize damage to tissues as the device is thrust forward.
Small openings along the sides of the cannula near the tip create
passages between the tissue and the central lumen of the cannula,
which is in fluid communication with a suction source, so that
tissue and fluids can be aspirated. The suction causes the adipose
tissue to be pulled into the openings along the sides of the
cannula, and the blunt dissection provided by the surgeon's
manipulation of the cannula tears the tissue. The fragments and
released fluids are then aspirated through the openings along the
sides of the cannula and then through the central lumen of the
cannula. Thus, these types of cannulae are designed to accomplish
two surgical objectives with a single device. First, they crush,
tear, or avulse the fatty tissues such that the tissue fragments
and fluids can pass through the openings in the sides of the
cannula. Second, the suction source and the central lumen of the
cannulae are used to aspirate the tissue fragments and fluids from
the operative site.
The liposuction procedure is referred to as a `closed` procedure
because the operative site about the tip of the cannula is not
directly visualized during the procedure due to the small incision
size and the length of the liposuction cannula, which results in
the tip area being buried inside the tissue. When a cannula is
placed into the fatty tissue through the small incision, a seal is
created between the outer surface of the cannula about and along
its length and the fatty tissue, preventing the flow of any ambient
pressure fluid, such as air, to the operative site about the tip of
the cannula. When suction is applied, there exists low pressure
inside the cannula at the operative site, the blunt tip area and
the side openings, that pulls the tissue into the side openings
which is then torn with the motion of the cannula. Because the seal
prevents the flow of any ambient pressure fluid to the operative
site about the tip or the cannula, the pressure about the tip of
the cannula quickly drops to the pressure of the suction source,
which is significantly below the ambient pressure. The combination
of the above-mentioned seal and the fact that the pressure at the
operative site about the tip of the cannula has dropped to the
pressure of the suction source greatly reduces, if not completely
eliminates, the surgeon's ability to remove tissue fragments and
fluids from the operative site because the pressure differential
between the operative site at the tip of the cannula and the
suction source has been eliminated. Thus, fragments and fluids move
not at all or very slowly through the cannula and suction tubing,
or clog the tubing. The tip of the cannula must be withdrawn from
the patient to such an extent that the seal is broken and the tip
and side openings are exposed to ambient air pressure to clear the
cannula and suction line. This phenomenon appears to the surgeon as
a `clogged` instrument or tubing set.
The liposuction procedure can be traumatic to the patient. The
mechanical disruption of the tissues may result in, among other
things, bleeding, bruising, temporary numbness, or swelling. The
procedure can also be physically demanding on the surgeon because
of the forces required to repeatedly push the cannula through the
tissue. Further, the final
cosmetic result is a function of the skill of the surgeon, the
patient, and the type of surgical instrumentation used in the
surgery.
Many patents disclose improvements and solutions for liposuction
cannulae. U.S. Pat. No. 4,596,553 to Lee discloses a suction
cannula with a guide bar attached to the cannula that is used to
control the depth of the cannula in the tissue relative to the
skin. U.S. Pat. No. 4,735,605 to Schwartz discloses a suction
cannula with an outer tube with a longitudinal slot, and an inner
tube with a spiral slot which is movable relative to the outer
tube. U.S. Pat. No. 5,112,302 to Cucin has a suction cannula with a
reciprocating means so that the cannula can be caused to
reciprocate relative to the handle. U.S. Pat. Nos. 5,348,535 and
5,643,198, also to Cucin, have a suction cannula with a hollow
outer cannula and a hollow inner cannula connected to a
reciprocating means. The hollow inner cannula reciprocates within
the hollow outer cannula so that tissue pulled into openings in the
hollow outer cannula is sheared between the two cannulae. U.S. Pat.
No. 5,181,907 to Becker has a tubular member with a plurality of
longitudinally extending members projecting radially outward beyond
the surface of the tubular member. U.S. Pat. No. 5,665,101 also to
Becker has a method of cutting tissue with a rotary powered
surgical instrument with an inner and an outer tube, both with
cutting windows on the sides of the tubes. U.S. Pat. No. 5,569,178
to Henley has a source of rotary power, an outer tubing, and an
inner tubing with flanges. U.S. Pat. No. 5,013,300 to Williams has
a single lumen cannula, a handle, a control means for varying the
suction forces, and a means to swivel the handle relative to the
cannula. This patent includes a means to vent the tubing set from
the handpiece back to the suction source, but does nothing to solve
the same problem for the cannula. Consequently, the seal and clog
problems persist.
While some of the patented devices have claimed improvements and
solutions to liposuction cannulae for the problems of tissue
trauma, surgeon fatigue, and cosmetic results, none address or
appreciate the above-mentioned seal and clog problems and all of
the prior devices incorporate tissue fragmentation and tissue
aspiration capability in but one cannula. All of these devices are
subject to clogging.
There is a need to improve the design of the prior patents to
further reduce trauma to the tissues of the patient, resulting in
reduced healing times, less bruising, less bleeding, and reduced
pain. Accordingly, it is the object of the instrument disclosed
herein to produce an improved surgical instrument for the removal
of fragmented tissues and fluids from a patient in a closed
procedure with minimal damage to remaining tissues and to further
increase the speed and thoroughness of the procedure by eliminating
the above-mentioned seal and clog problems inherent in this closed
procedure and therefore eliminating the clogging of previous
designs.
SUMMARY OF THE INVENTION
It is a general object of the present invention to provide an
improved surgical instrument for the removal of fragmented tissues
and fluids from a patient through a small incision.
It is a further object of the present invention to provide a
surgical instrument for the above-mentioned purpose that causes
minimal trauma to all contacted tissues and thus provides decreased
healing time, decreased patient pain, and reduced swelling,
bleeding, and bruising.
It is a still further object of the present invention to provide a
surgical instrument for the aspiration of fragmented tissues of a
patient that does not clog.
It is yet a still further object of the present invention to
provide a surgical instrument for the aspiration of fragmented
tissues of a patient that provides simultaneous aspiration and
irrigation.
The aforementioned objects of the present invention are
accomplished by separating the tissue fragmentation aspect of the
liposuction procedure from the aspiration aspect of the procedure
and by providing a pressure vent capability using a multi-lumen
cannula that prevents clogging.
The instrument disclosed is specifically designed for aspiration of
fragmented tissues and fluids from a patient, and thus is not
primarily intended to be used to fragment, tear, or avulse tissues.
The fragmentation of the tissues is preferably accomplished with
other instruments or devices primarily designed for tissue
fragmentation, for example, either a direct application of
appropriate ultrasonic energy or a transdermal application of
appropriate ultrasonic energy. Further, the disclosed surgical
instrument may provide simultaneous suction and irrigation in
separate passages of a multi-lumen cannula. The irrigation fluid
may suspend and dilute the fragmented tissues, making aspiration
easier. An irrigation passage of the multi-lumen cannula provides a
pressure vent that solves the above-mentioned seal problem and
therefore eliminates the clogging problem. A suction passage and
the irrigation passage are sized and shaped so that the resistance
to flow is approximately equal in each passage, appropriately
adjusted for changes in the viscosity between the irrigant and the
aspirant. Still further, a vent passageway is provided on a handle
to change the suction between the suction passage in the cannula
and ambient air about the handle so that the surgeon can control
the application of the suction about the tip of the cannula from
the handle. A switch may be provided on the handle to initiate or
inhibit the flow of irrigation fluid through the irrigation passage
in the cannula.
In general the surgical aspirator and irrigator system is comprised
of a source of suction, a source of irrigation fluid, and a handle
to be held and manipulated by the surgeon. The source of suction
may be the wall suction present in the operating room or it may be
from a separate suction pump specifically designed for the
lipoplasty procedure. The preferred method to deliver the
irrigation fluid is to use a peristaltic pump and tubing set. The
handle has a suction connector for fluid communication with the
source of suction and an irrigation connector for fluid
communication with the source of irrigation fluid. The preferred
connector for both suction and irrigation is a tubing barb threaded
into the handle. The handle has a suction channel in fluid
communication with the suction connector, an irrigation channel in
fluid communication with the irrigation connector, and a vent
passageway in fluid communication between the ambient air and the
suction channel.
A multi-lumen cannula having at least two passages along an axis
thereof is supported on the distal end of the handle. The preferred
outside diameter for the multi-lumen cannula is between three and
six millimeters. The multi-lumen cannula has a first passage for
suction that is in fluid communication with the suction channel and
a second passage for irrigation that is in fluid communication with
the irrigation channel. The multi-lumen cannula has a cross-section
perpendicular to the axis, the cross-section located anywhere along
the length of the multi-lumen cannula. The first passage has a
surface area of a unit length measured from the cross-section and a
cross-sectional area at the cross-section. The surface area of a
unit length of the first passage can be calculated by multiplying
the total perimeter of the first passage measured in centimeters by
a unit length, which is one centimeter. The total perimeter may
have one component such as the inside circumference of a circular
tube or it may have two components if one passage contains the
other passage, in which case the total perimeter, for example, is
the sum of the inside circumference of an outer circular tube and
the outside circumference of a second circular tube contained
within outer circular tube. The first passage has a resistive ratio
that is the surface area of a unit length of the first passage
divided by the cross-sectional area of the first passage. The
second passage has a surface area of a unit length measured from
the cross-section and a cross-sectional area of the second passage
at the cross-section. The surface area of a unit length of the
second passage can be calculated as described above using the
dimensions of the second passage. The second passage has a
resistive ratio that is the surface area of the unit length of the
second passage divided by the cross-sectional area of the second
passage. The resistive ratio of the first passage is between 0.5
and 1.5 times the resistive ratio of the second passage. The
preferred value is slightly less than 1.0 to account for the
increase in viscosity of the aspirant relative to the irrigant.
Thus, it is preferred that the resistive ratio of the first passage
be between 0.7 and 0.9 times the resistive ratio of the second
passage.
In a preferred embodiment of the surgical aspirator and irrigator
system the multi-lumen cannula may include a hollow outer tube with
an inner surface about and along its length and a hollow inner tube
residing within the hollow outer tube with an outer surface about
and along its length. The preferred material for both tubes is
thin-walled stainless steel tubing. The hollow inner tube has a
lumen, preferably circular, the lumen being the second passage for
irrigation. An annular space is located between the outer surface
of the hollow inner tube and the inner surface of the hollow outer
tube, the annular space being the first passage for suction.
In another embodiment of the surgical aspirator and irrigator
system the multi-lumen cannula may include a hollow outer tube with
an inner surface about and along its length and a hollow inner tube
residing within the hollow outer tube with an outer surface about
and along its length. The preferred material for both tubes is
thin-walled stainless steel tubing. The hollow inner tube has a
lumen, preferably circular, the lumen being the first passage for
suction. An annular space is located between the outer surface of
the hollow inner tube and the inner surface of the hollow outer
tube, the annular space being the second passage for
irrigation.
The multi-lumen cannula may include a patient tip disposed away
from the distal end of the handle with a blunt or bullet-nosed
shape. The blunt or bullet-nosed shape of the tip is to smooth
passage of the multi-lumen cannula through the tissues, thereby
reducing trauma to the tissues and reducing the force required by
the surgeon to push the multi-lumen cannula through the tissues.
The preferred material for the patient tip is stainless steel.
Polymers such as polycarbonate, polyurethane, or polyethylene may
also be used. There may be one or more ports in or near the patient
tip for providing fluid communication between the tissue and the
first passage of the multi-lumen cannula. The one or more ports may
be part of the patient tip or they may be part of the multi-lumen
cannula near the patient tip. There may be one or more holes in or
near the patient tip for providing fluid communication between the
second passage of the multi-lumen cannula and the tissue. The one
or more holes may be part of the patient tip or they may be part of
the multi-lumen cannula near the patient tip.
The handle of the surgical aspirator and irrigator system may
include a vent valve operatively coupled to the vent passageway for
selectively establishing fluid communication between the ambient
air and the suction channel that passes through the handle when the
vent valve is open. The preferred method for creating the vent
valve is to provide access to the ambient air orifice of the vent
passageway so that the surgeon can open or occlude the orifice with
his thumb or finger. A sliding or rotating mechanism that opens or
occludes the vent passageway may also be used.
The handle may include an irrigation control switch with an
electrical connection to an irrigation controller located at and
operatively connected to the source of irrigation fluid. The
irrigation control switch is used for initiating or inhibiting the
flow of irrigation fluid by electrically signaling the irrigation
controller through the electrical connection in circuit therewith.
The preferred style of irrigation switch is a two-position
push-button toggle switch.
The preferred irrigation fluid is a supply of sterile,
biocompatible irrigation fluid such as sterile saline. The
irrigation fluid may be a supply of filtered, pressurized,
biocompatible gas such as carbon dioxide or air.
In a further embodiment the surgical aspirator and irrigator system
may include a supply of sterile, biocompatible irrigation fluid, a
supply of filtered, pressurized, biocompatible gas, and a gas
connector located on the handle in fluid communication with the
supply of filtered, pressurized, biocompatible gas. The handle has
a gas channel in fluid communication with the gas connector and a
two-input one-output connector. The two-input one-output connector
is also commonly referred to as a `Y fitting`. A first input on the
two-input one-output connector is in fluid communication with the
gas channel passing through the handle and a second input on the
two-input one-output connector is in fluid communication with the
irrigation channel passing through the handle. The preferred method
of creating the gas channel is to use a piece of silicone tubing
between the gas connector and the first input. An output on the
two-input one-output connector is in fluid communication with the
second passage in the multi-lumen cannula. A gas control valve may
be located on the handle. The gas control valve selectively opens
or closes so that the gas channel passing through the handle is in
fluid communication with the first input on the two-input
one-output connector when the gas control valve is open or so that
the gas channel is sealed from fluid communication with the first
input on the two-input one-output connector when the gas control
valve is closed. The preferable method of creating the gas control
valve is to use a spring and wedge to pinch and occlude the gas
channel that has been formed with a piece of silicone tubing.
A method of using an aspirator and irrigator system that has a
source of suction and a source of irrigation fluid is also claimed.
The method has the steps of inserting a multi-lumen cannula into
fragmented medium, applying suction to a first passage of the
multi-lumen cannula, irrigating through a second passage of the
multi-lumen cannula, using a handle on the multi-lumen cannula to
manipulate the aspirator and irrigator within the medium to the
desired areas of fragmented medium, sucking and/or irrigating to
most effectively remove fragmented medium, removing the aspirator
and irrigator system from the fragmented medium.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features of the invention are set forth in the appended
claims. The invention will be best understood by reference to the
following figures when read in conjunction with the detailed
description of the invention.
FIG. 1 is a partial schematic representation of the present
invention.
FIG. 1a is an end view of the multi-lumen cannula of FIG. 1.
FIG. 2 is a partial schematic representation of the multi-lumen
cannula with the irrigation passage being the lumen of the hollow
inner tube.
FIG. 2a is an end view of the multi-lumen cannula of FIG. 2.
FIG. 3 is a partial schematic representation of the multi-lumen
cannula with the suction passage being the lumen of the hollow
inner tube.
FIG. 3a is an end view of the multi-lumen cannula of FIG. 3.
FIG. 4 is a partial schematic representation of a patient tip for
the multi-lumen cannula shown in FIG. 1 and FIG. 1a.
FIG. 5 is a partial schematic representation of a patient tip for
the multi-lumen cannula shown in FIG. 2 and FIG. 2a.
FIG. 6 is a partial schematic representation of a patient tip for
the multi-lumen cannula shown in FIG. 3 and FIG. 3a.
FIG. 7 is a partial schematic representation of the handle showing
the vent valve, the vent passageway, the irrigation control switch,
and the irrigation controller.
FIG. 8 is a partial schematic representation of the handle showing
the gas valve, the gas channel, and the two-input one-output
connector.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, FIG. 1 is a partial schematic
representation of the apparatus embodying this invention. In
general the surgical aspirator and irrigator system 10 is comprised
of a source of suction 11, a source of irrigation fluid 12, and a
handle 13 to be held and manipulated by the surgeon. The source of
suction may be the wall suction present in the operating room or it
may be from a separate suction pump specifically designed for the
lipoplasty procedure. The preferred method to deliver the
irrigation fluid is to use a peristaltic pump and tubing set. The
handle
13 has a suction connector 15 for fluid communication with the
source of suction 11 and an irrigation connector 16 for fluid
communication with the source of irrigation fluid 12. The preferred
connector for both suction and irrigation is a tubing barb threaded
into the handle 13. The handle 13 has a suction channel 17 in fluid
communication with the suction connector 15, an irrigation channel
18 in fluid communication with the irrigation connector 16, and a
vent passageway 32 in fluid communication between the ambient air
about the handle 13 and the suction channel 17.
A multi-lumen cannula 19 having at least two passages along an axis
36 thereof is supported on the distal end 14 of the handle 13. The
preferred outside diameter for the multi-lumen cannula is between
three and six millimeters. The multi-lumen cannula has a first
passage 20 for suction that is in fluid communication with the
suction channel 17 and a second passage 21 for irrigation that is
in fluid communication with the irrigation channel 18. The S-shaped
double lines 37 shown in FIG. 1 indicate a break-in-length and are
used to scale the diagram to fit on one page. The S-shaped double
lines 37 are not part of the invention.
The multi-lumen cannula 19 has a cross-section perpendicular to the
axis 36, the cross-section located anywhere along the length of the
multi-lumen cannula, as shown in FIG. 1a. The first passage 20 has
a surface area of a unit length measured from the cross-section and
a cross-sectional area at the cross-section. The surface area of a
unit length of the first passage 20 can be calculated by
multiplying the total perimeter of the first passage 20 measured in
centimeters by a unit length, which is one centimeter. The total
perimeter may have one component such as the inside circumference
of a circular tube or it may have two components if one passage
contains the other passage, in which case the total perimeter, for
example, is the sum of the inside circumference of an outer
circular tube and the outside circumference of a second circular
tube contained within outer circular tube. The first passage 20 has
a resistive ratio that is the surface area of a unit length of the
first passage 20 divided by the cross-sectional area of the first
passage 20. The second passage 21 has a surface area of a unit
length measured from the cross-section and a cross-sectional area
of the second passage 21 at the cross-section. The surface area of
a unit length of the second passage can be calculated as described
above using the dimensions of the second passage 21. The second
passage 21 has a resistive ratio that is the surface area of the
unit length of the second passage divided by the cross-sectional
area of the second passage 21. The resistive ratio of the first
passage 20 is between 0.5 and 1.5 times the resistive ratio of the
second passage 21. The preferred value is slightly less than 1.0 to
account for the increase in viscosity of the aspirant relative to
the irrigant. Thus, it is preferred that the resistive ratio of the
first passage 20 be between 0.7 and 0.9 times the resistive ratio
of the second passage 21.
The preferred embodiment of the multi-lumen cannula 19 is shown in
FIG. 2. A cross-section of the multi-lumen cannula 19 for this
embodiment is shown in FIG. 2a. The multi-lumen cannula 19 may
include a hollow outer tube 22 with an inner surface 26 about and
along its length and a hollow inner tube 23 residing within the
hollow outer tube 22 with an outer surface 25 about and along its
length. The preferred material for both tubes is thin-walled
stainless steel tubing. The lumen of the hollow inner tube 23 is
preferably circular and is the second passage 21 of the multi-lumen
cannula 19 for irrigation. An annular space is located between the
outer surface 25 of the hollow inner tube 23 and the inner surface
26 of the hollow outer tube 22, the annular space being the first
passage 20 of the multi-lumen cannula 19 for suction. The S-shaped
double lines 37 shown in FIG. 2 indicate a break-in-length and are
used to scale the diagram to fit on one page. The S-shaped double
lines 37 are not part of the invention.
Another embodiment of the multi-lumen cannula 19 is shown in FIG.
3. A cross-section of the multi-lumen cannula 19 for this
embodiment is shown in FIG. 3a. The multi-lumen cannula 19 may
include a hollow outer tube 22 with an inner surface 26 about and
along its length and a hollow inner tube 23 residing within the
hollow outer tube 22 with an outer surface 25 about and along its
length. The preferred material for both tubes is thin-walled
stainless steel tubing. The lumen of the hollow inner tube 23 is
preferably circular and is the first passage 20 of the multi-lumen
cannula 19 for suction. An annular space is located between the
outer surface 25 of the hollow inner tube 23 and the inner surface
26 of the hollow outer tube 22, the annular space being the second
passage 21 of the multi-lumen cannula 19 for irrigation. The
S-shaped double lines 37 shown in FIG. 3 indicate a break-in-length
and are used to scale the diagram to fit on one page. The S-shaped
double lines 37 are not part of the invention.
A partial schematic diagram of a patient tip 28 is shown in FIG. 4.
The patient tip 28 shown in FIG. 4 mates with the multi-lumen
cannula 19 shown in FIG. 1 and FIG. 1a. The patient tip 28 is
disposed away from the distal end of the handle and has a blunt or
bullet-nosed shape. The blunt or bullet-nosed shape of the tip is
to smooth passage of the multi-lumen cannula 19 through the
tissues, thereby reducing trauma to the tissues and reducing the
force required by the surgeon to push the multi-lumen cannula 19
through the tissues. The preferred material for the patient tip is
stainless steel. Polymers such as polycarbonate, polyurethane, or
polyethylene may also be used. There may be one or more ports 29 in
or near the patient tip 28 for providing fluid communication
between the tissue and the first passage 20 of the multi-lumen
cannula 19. The one or more ports 29 may be part of the patient tip
28 or they may be part of the multi-lumen cannula 19 near the
patient tip 28. There may be one or more holes 30 in or near the
patient tip 28 for providing fluid communication between the second
passage 21 of the multi-lumen cannula 19 and the tissue. The one or
more holes 30 may be part of the patient tip 28 or they may be part
of the multi-lumen cannula 19 near the patient tip 28. The S-shaped
double lines 37 shown in FIG. 4 indicate a break-in-length and are
used to scale the diagram to fit on one page. The S-shaped double
lines 37 are not part of the invention.
A partial schematic diagram of the preferred embodiment of a
patient tip 28 is shown in FIG. 5. The patient tip 28 shown in FIG.
5 mates with the multi-lumen cannula 19 shown in FIG. 2 and FIG.
2a. The patient tip 28 is disposed away from the distal end of the
handle and has a blunt or bullet-nosed shape. The blunt or
bullet-nosed shape of the tip is to smooth passage of the
multi-lumen cannula 19 through the tissues, thereby reducing trauma
to the tissues and reducing the force required by the surgeon to
push the multi-lumen cannula 19 through the tissues. The preferred
material for the patient tip is stainless steel. Polymers such as
polycarbonate, polyurethane, or polyethylene may also be used.
There may be one or more ports 29 in or near the patient tip 28 for
providing fluid communication between the tissue and the first
passage 20 of the multi-lumen cannula 19. The one or more ports 29
may be part of the patient tip 28 or they may be part of the
multi-lumen cannula 19 near the patient tip 28. There may be one or
more holes 30 in or near the patient tip 28 for providing fluid
communication between the second passage 21 of the multi-lumen
cannula 19 and the tissue. The one or more holes 30 may be part of
the patient tip 28 or they may be part of the multi-lumen cannula
19 near the patient tip 28. The S-shaped double lines 37 shown in
FIG. 5 indicate a break-in-length and are used to scale the diagram
to fit on one page. The S-shaped double lines 37 are not part of
the invention.
A partial schematic diagram of a third embodiment of a patient tip
28 is shown in FIG. 6. The patient tip 28 shown in FIG. 6 mates
with the multi-lumen cannula 19 shown in FIG. 3 and FIG. 3a. The
patient tip 28 is disposed away from the distal end of the handle
and has a blunt or bullet-nosed shape. The blunt or bullet-nosed
shape of the tip is to smooth passage of the multi-lumen cannula 19
through the tissues, thereby reducing trauma to the tissues and
reducing the force required by the surgeon to push the multi-lumen
cannula 19 through the tissues. The preferred material for the
patient tip is stainless steel. Polymers such as polycarbonate,
polyurethane, or polyethylene may also be used. There may be one or
more ports 29 in or near the patient tip 28 for providing fluid
communication between the tissue and the first passage 20 of the
multi-lumen cannula 19. The one or more ports 29 may be part of the
patient tip 28 or they may be part of the multi-lumen cannula 19
near the patient tip 28. There may be one or more holes 30 in or
near the patient tip 28 for providing fluid communication between
the second passage 21 of the multi-lumen cannula 19 and the tissue.
The one or more holes 30 may be part of the patient tip 28 or they
may be part of the multi-lumen cannula 19 near the patient tip 28.
The S-shaped double lines 37 shown in FIG. 6 indicate a
break-in-length and are used to scale the diagram to fit on one
page. The S-shaped double lines 37 are not part of the
invention.
A partial schematic diagram of the handle 13 of the surgical
aspirator and irrigator system 10 is shown in FIG. 7. The handle 13
may include a vent valve 31 operatively coupled to the vent
passageway 32 for selectively establishing fluid communication
between the ambient air about the handle 13 and the suction channel
17 that passes through the handle 13. The preferred method for
creating the vent valve 31 is to provide access to the ambient air
orifice of the vent passageway 32 so that a surgeon can open or
occlude the orifice with his thumb or finger. A sliding or rotating
mechanism that opens or occludes the vent passageway 32 may also be
used.
The handle may include an irrigation control switch 33 with an
electrical connection 34 to an irrigation controller 35 located at
and operatively connected to the source of irrigation fluid 12. The
irrigation control switch 33 is used for initiating or inhibiting
the flow of irrigation fluid by electrically signaling the
irrigation controller 35 through the electrical connection 34 in
circuit therewith. The preferred style of irrigation switch is a
two-position push-button toggle switch. The S-shaped double lines
37 shown in FIG. 7 indicate a break-in-length and are used to scale
the diagram to fit on one page. The S-shaped double lines 37 are
not part of the invention.
A final embodiment of the surgical aspirator and irrigator system
10 is shown in FIG. 8. The handle 13 may include a gas connector 36
located on the handle 13 in fluid communication with a supply of
filtered, pressurized, biocompatible gas. The handle has a gas
channel 43 in fluid communication with the gas connector 36 and a
first input 39 of a two-input one-output connector 38. The
two-input one-output connector 38 is also commonly referred to as a
`Y fitting`. A second input 40 of the two-input one-output
connector 38 is in fluid communication with the irrigation channel
18 passing through the handle 13. The preferred method of creating
the gas channel 43 is to use a piece of silicone tubing between the
gas connector 36 and the first input 39. An output 41 of the
two-input one-output connector 38 is in fluid communication with
the second passage 21 in the multi-lumen cannula 19. A gas control
valve 42 may be located on the handle 13. The gas control valve 42
selectively opens or closes so that the gas channel 43 passing
through the handle 13 is in fluid communication with the first
input 39 on the two-input one-output connector 38 when the gas
control valve 42 is open or so that the gas channel 43 is sealed
from fluid communication with the first input 39 on the two-input
one-output connector 38 when the gas control valve 42 is closed.
The preferable method of creating the gas control valve 42 is to
use a spring and wedge to pinch and occlude the gas channel 43 that
has been formed with a piece of silicone tubing. The S-shaped
double lines 37 shown in FIG. 8 indicate a break-in-length and are
used to scale the diagram to fit on one page. The S-shaped double
lines 37 are not part of the invention.
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